Ante-mortem diagnostics for anticoagulant rodenticide toxicosis in red-tailed hawks (Buteo jamaicensis)
Noha Abou-Madi, DVM, MSc, DACZM; Clinical Associate Professor, Clinical Sciences
Elizabeth Bunting, VMD; Senior Extension Associate, Animal Health Diagnostic Center
Marjory Brooks, DVM, DACVIM; Director Comparative Coagulation Laboratory, Population Medicine
Free-ranging raptors, including red-tailed hawks (Buteo jamaicensis) are commonly exposed to anticoagulant rodenticides (ARs) through consumption of intoxicated rodent prey. Animals with acute, high-level rodenticide exposure develop a coagulopathy that is often fatal if not diagnosed and treated in a timely manner. The cumulative effect of repeated, low-level exposure events is unknown. There is currently a lack of standardized, clinically relevant diagnostic tests to detect AR-related coagulopathy in raptors that present to wildlife veterinarians. This may result in widespread underdiagnosis of coagulopathy related to AR toxicosis, and underestimation of the clinical effects of repeat, sub-lethal AR exposure in birds of prey. To address this problem, this study investigates two affordable, practical tests of coagulation, the Russell’s viper venom time (RVVT) and plasma protein C, in red-tailed hawks. The study will first establish reference ranges for coagulation parameters in captive, healthy, red-tailed hawks. We will then determine if prolonged RVVT and/or decreased protein C levels are useful predictors of AR exposure in this species, regardless of clinical signs. Sick and injured red tailed hawks presenting to the Cornell Wildlife Health Center will be sampled for coagulation testing and blood rodenticide concentration, and we will test for significant correlations between RVVT, protein C concentration, and rodenticide exposure.